Chinese Paralytic Syndrome (CPS) is a recently described form of acute onset flaccid paralysis, primarily involving children in rural areas of Northern China. The review of over 3000 cases and personal examination of 88 patients indicates that this is a non-inflammatory motor neuropathy with distinct epidemiologic, clinical, physiologic, and pathologic features. These preliminary studies indicate that CPS differs from poliomyelitis and the demyelinative form of the Guillain-Barre Syndrome (GBS). In addition, serologic studies suggest an association with Campylobacter jejuni. To amplify our preliminary studies, the following specific aims are proposed. In collaboration with our Chinese colleagues, Aim 1 is designed to study prospectively and longitudinally, 50 patients and suitable controls in terms of clinical progression, electrophysiologic alterations, and serum antibody responses; to evaluate the pathophysiology of weakness and recovery; and to determine the incidence of the disease in a separate, defined population. Aim 2 is designed to establish definitively how CPS differs from other forms of acute onset flaccid paralysis. Lastly, Aim 3 seeks to uncover underlying mechanisms such as the role of C. jejuni and host immunologic responses. Surveillance campaigns for poliomyelitis indicate that there are significant numbers of children with acute onset flaccid paralysis who do not have polio. It is our hypothesis that a disorder similar, if not identical, to CPS occurs with a high incidence in other developing nations, particularly in Latin America.